As a method of separating stacked sheets one by one from above and carrying them, a negative pressure suction scheme using vacuum pads is known well.
This scheme does not depend on the rigidity of a medium, and is therefore usable in a page turning apparatus for a booklet having a plurality of high rigidity pages.
The vacuum pads themselves are also rich in variety to cope with the properties of media. Some vacuum pads have the rotation axis of swinging motion to permit rotation about the center of gravity upon lifting a medium. Some vacuum pads can deform by themselves (by using a rubber material or having a bellows structure).
A page turning apparatus using vacuum pads is one of processing units of a booklet printer. The booklet printer is formed by connecting a plurality of processing units via feed paths. A booklet is subjected to predetermined processing in each processing unit, and then fed to the processing unit connected next.
The booklet is fed to a page turning position to turn pages. A feed guide is provided on the page turning position so as to regulate rising of a page due to the booklet's inclination to close and ensure satisfactory feed.
However, when the feed guide is provided, it needs to retreat to prevent interference during the page turning operation. In addition, since mechanisms for realizing page turning are densely arranged near the page turning position so as to make the structure complex, the mechanism for causing the feed guide to retreat also becomes complex.
An apparatus capable of regulating rising of a booklet page without needing a complex mechanism is desired.